Devil May Cry walkthrough/M23

When the game resumes, a clock starts counting down. You have five minutes to get out of the Underworld and off the island! Use your Devil Trigger liberally to increase your running speed and defeat enemies faster. Run out of Mundus's throne room, get out of the heart chamber, and in the circular room there is a Frost. You don't have to kill it, so bypass it for now if you think you'll need the time.

In the room where you fought Nightmare, there are a couple of Nobodies. Kill them to unlock the doors and move forward. The next room has another Frost in it, but you can run past it. Run down the hallway to the red glowing thing that will take you back to the Mirror World.

From the mirror cathedral, run around the hole in the floor and jump on the floating platform to go back to the regular cathedral. Now starts the real mission!

Walkthrough
The timer will resume counting down from however long you had left at the end of the mission lead-in. In the Cathedral, there are some Marionettes laying around. You can bypass these as well if you're short on time.

Run down the hallway towards the far end. There are two Blades here that must be killed in order to unlock the Sealed Door. Head through it and into the airplane hangar.

As you step into the hangar, a cutscene will occur in which the floor will collapse and dump Dante in the canal system. Here, Mundus makes his last stand!

Boss: Mundus
Compared to last mission, this one is a breeze, but don't let your guard down, either. Attack and jump to dodge his eye lasers. His health falls relatively fast. A good Air Raid or Vortex will cut him down to about half health. Once this happens, another cutscene will happen, where Dante suddenly looks as though he's losing. Then, who appears but Trish! She's here to help Dante destroy her former master, and she loans him her lightning power!

At this point, stay back from Mundus and use your firearms to charge your Devil Trigger. He has those stringy worm-things growing out of him now that will snag and damage you if you get close. Once you have three runes filled up, activate Devil Trigger and fire at him again for the win!

Walkthrough Part 2
Just because Mundus is defeated doesn't mean Dante is out of the woods yet. Watch the cutscene, and get ready for another rail shooter mini-game.

You must navigate the caves underneath Mallet Island. Dodge the stalagmites and stalagtites as much as you can, and shoot the ones in your way with your ranged attack. If you run into something, your health with drop a little, but fortunately, you start this with full health.

Once you successfully escape, you're home free! Watch the cutscene and give yourself a well-earned pat on the back!

You've beat the game!